11. A company produces precision 1 meter (1000 mm) rulers. The actual distributi

Question

11.

A company produces precision 1 meter (1000 mm) rulers. The actual distribution of lengths of the rulers produced by this company is Normal, with mean and standard deviation = 0.02 mm. Suppose I select a simple random sample of four of the rulers produced by the company and I measure their lengths in mm. The sample yields = 1000. A 90% confidence interval for is:

A) 1000.00 ± 0.0196.

B) 1000.00 ± 0.0115.

C) 1000.00 ± 0.0165.

D) 1000.00 ± 0.0082.

12. If the confidence level is increased from 90% to 99% for an SRS of size n, the width of the confidence interval for the mean will:

A) stay the same.

B) The answer cannot be determined with the information given.

C) decrease.

D) increase.

Explanation / Answer

we are give that Standard dev = 0.02 and sample size n = 4

standard error = stdev/sqrt(n) = 0.02/sqrt(4) = 0.01

Critical value for alpha 0.10 = +1.645

Margin of error = Critical value * std error = +1.645 * 0.01 =+ 0.0165

Confidence interval = sample mean + margin of error = 1000.00+ 0.0165

Ans) C 1000.00 + 0.0165

12. When we increase confidence level, the width of interval increase because higher values of critical values.

Hope this will helps you. Please thumbs up if its right answer. Thanks and God bless You :)

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.